Where there are joints ,down pipes etc. a white deposit has appeared over time at all joints.
I guess because we are in a hard water area.
The question is how to remove it without scraping it or wire brushing it as obviously it will scratch the plastic.
I’ve tried silicon n WD40 without success...
Unable to have a concrete base, would slabs on a bed of sand be strong enough, at the moment the ground is rough ground. Nothing heavy going in, 8x6. Thank you !